I am an Indian, ravaged by the Covid-19 pandemic in my country. I come from a non engineering background (Physics). I was thinking about the following.
If one has an oxygen concentrator, i.e. a device which removes impurities such as N2 and CO2 from air, to release pure oxygen (-93%) using electricity.
https://en.wikipedia.org/wiki/Oxygen_concentrator
It supplies oxygen at the rate of 5 liters / min. Can it be used to fill multiple empty oxygen cylinder, which are basically pressurized oxygen kept in cans. This way, if there are multiple patients suffering from Covid-19, they can be supplied oxygen using the multiple cylinders. Is there any simple and efficient way for one to fill the cylinders with oxygen, bear in mind the cylinders are having oxygen at very high pressure.